阅读说明：本技术 一种低温脱硫、脱硝催化剂及其制备方法 (Low-temperature desulfurization and denitrification catalyst and preparation method thereof ) 是由 贾成 佘振宝 刘长余 杨建忠 闫禹 于 2020-07-24 设计创作，主要内容包括：本发明公开了一种低温脱硫脱硝催化剂及其制备方法。所述低温脱硫脱硝催化剂以廉价的粘土和粉煤灰作为催化剂载体,先经过硝酸预氧化(酸化),将低温催化剂的活性成分用盐酸溶解,再用等量浸渍的方法,使金属氧化物附着在低温脱硫脱硝催化剂的载体上,成为低温脱硫脱硝催化剂。本发明所述的低温脱硫脱硝催化剂制作工艺简单,成本低,能够实现在脱硫同时也可以脱硝的技术效果,且使用方法简便,降低了企业的治理成本和治理难度,具有巨大的工业应用价值。(The invention discloses a low-temperature desulfurization and denitrification catalyst and a preparation method thereof. The low-temperature desulfurization and denitrification catalyst takes low-cost clay and fly ash as catalyst carriers, the active ingredients of the low-temperature catalyst are firstly dissolved by hydrochloric acid through nitric acid pre-oxidation (acidification), and then the metal oxides are attached to the carriers of the low-temperature desulfurization and denitrification catalyst by an equivalent impregnation method to form the low-temperature desulfurization and denitrification catalyst. The low-temperature desulfurization and denitrification catalyst disclosed by the invention is simple in preparation process and low in cost, can realize the technical effect of desulfurization and denitrification, is simple and convenient to use, reduces the treatment cost and treatment difficulty of enterprises, and has a huge industrial application value.)

1. The low-temperature desulfurization and denitrification catalyst is characterized by comprising a catalyst carrier, wherein a catalyst active component is loaded on the catalyst carrier;

wherein the catalyst support comprises the following components:

the catalyst active ingredients comprise the following components by weight of the catalyst carrier:

2. the low-temperature desulfurization and denitrification catalyst according to claim 1, wherein the molar ratio of the element Mn to the element Ce in the catalyst is 4: 1.

3. The low-temperature desulfurization and denitrification catalyst according to claim 1, wherein the content of the oxide of Mn is 5-25 wt% based on 100% by mass of the metal oxide; the content of the oxide of Ce is 1-4 wt%.

4. The low-temperature desulfurization and denitrification catalyst according to claim 1, wherein the clay material is one or more of kaolinite clay, sericite clay and montmorillonite clay.

5. The low-temperature desulfurization and denitrification catalyst according to claim 1, wherein the ignition loss agent is flour.

6. The preparation method of the low-temperature desulfurization and denitrification catalyst according to claims 1-5, characterized by comprising the following steps:

(1) mixing the raw materials of the catalyst carrier in proportion, adding a proper amount of water, uniformly stirring into a mud shape, and placing the mud in a cool and dry place for aging;

(2) molding or extruding the aged mud-like substance by a molding press or an extruder to obtain a catalyst green body;

(3) placing the green body in a shade drying place for naturally drying in the shade for 24h, then drying for 2-4h by hot air at 200 ℃, placing the dried catalyst green body in a muffle furnace, and roasting for 8h at 950 ℃ to obtain a multi-gap foam ceramic-based catalyst green body;

(4) immersing the porous foam ceramic-based catalyst blank into a nitric acid solution with the concentration of 35%, soaking for 2h, and naturally drying in the shade to obtain a catalyst carrier;

(5) weighing the catalyst active ingredients according to a proportion, slowly adding the weighed catalyst active ingredients into a 25% hydrochloric acid solution for multiple times, and fully stirring to prepare a hydrochloric acid solution containing the catalyst active ingredients;

(6) soaking a catalyst carrier in a hydrochloric acid solution containing a catalyst active component for 2-4h, taking out, and drying by hot air at 200 ℃ for 10-24 h;

(7) and (3) placing the dried catalyst carrier in a muffle furnace, and heating for 8-15h at the temperature of 200-250 ℃ to obtain a finished product of the low-temperature desulfurization and denitrification catalyst.

7. The method for preparing a catalyst for low-temperature desulfurization and denitrification according to claim 6, wherein the volume of the hydrochloric acid solution in the step (4) is calculated from the water absorption of the catalyst carrier. The water absorption of the catalyst carrier is determined by experimental data obtained from practical experiments, and the water absorption of a general catalyst carrier is 38% -50%.

8. The method for preparing the catalyst for low-temperature desulfurization and denitration according to claim 6, wherein the drying method in the step (5) is one of hot air drying, infrared drying, microwave drying and natural drying.

9. The method for preparing a low-temperature desulfurization and denitrification catalyst according to claim 3, wherein the heating temperature in the step (6) is 220 ℃ to 240 ℃.

10. The method for preparing a low-temperature desulfurization and denitrification catalyst according to claim 3, wherein the heating temperature in step (6) is 230 ℃.

Technical Field

The invention relates to the field of catalysts and preparation thereof, in particular to a catalyst containing manganese cerium iron copper oxide.

Background

At present, the air pollution condition in China is increasingly serious, wherein the smoke emission of a boiler (kiln) is huge, and the air quality in China is seriously influenced. The flue gas of the boiler (kiln) contains a large amount of sulfur dioxide (SO)₂) And Nitrogen Oxides (NO)_x) And both are also the main components of haze and the main pollution source of atmospheric pollution. Therefore, sulfur dioxide (SO) in flue gas of boiler (kiln)₂) And Nitrogen Oxides (NO)_x) Becomes one of the key pollutants for prevention and treatment in China. Since the 70 s of the 20 th century, the nation has successively made strict restrictions on the emission of nitric oxide from coal-fired industrial boilers (kilns), and as scientific and technical and economic construction progresses, the restrictions on the emission have become more and more strict.

During the combustion process of coal, most of combustible substances in the coal can be burnt out in a kiln, and the rest of non-combustible substances are mainly ash, and the non-combustible ash and gas are combined together to form a large amount of waste flue gas containing a large amount of SO₂、NO、CO、CO₂And hydrocarbons, which are major sources of atmospheric environmental pollution.

At present, in the aspect of preparing the boiler (kiln) flue gas desulfurization and denitration catalysts at home and abroad, NO is removed by independently preparing_xCatalyst and SO removal₂The catalyst is the main catalyst. The environmental protection design unit is in the process of treating the flue gas of the boiler (kiln) to remove NO_xSO removal₂In the technical design aspect, the SO in the waste flue gas also needs to be determined₂And NO_xContent of (A) and SO in the local environmental protection sector₂And NO_xRespectively designed and manufactured to remove NO_xAnd SO removal₂Two different reaction devices are used, and then the two devices are arranged in a front-to-back order. In the practical application process, there are several important problems in such an approach: firstly, the design process is complex; secondly, the occupied area is large; thirdly, the manufacturing cost and the energy consumption are high; fourthly for environmental management enterprisesTreatment costs and treatment difficulties are increased. These problems are NO_xAnd SO₂The treatment of (a) presents significant difficulties and challenges.

At present, the prior art does not have any reference to the capability of removing SO₂While removing NO_xThe preparation of the catalyst and the related application technology. Therefore, the method can be prepared under the low-temperature (160-250 ℃) environment without using a reducing agent and can remove SO in flue gas of an industrial boiler (kiln)₂Can remove NO at the same time_xThe catalysts of (a) have great industrial application requirements.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a low-temperature desulfurization and denitrification catalyst and a preparation method thereof.

In order to solve the technical problems, the invention adopts the following technical scheme:

the low-temperature desulfurization and denitrification catalyst comprises a catalyst carrier, wherein a catalyst active component is loaded on the catalyst carrier.

The catalyst carrier consists of the following components:

the catalyst active ingredients comprise the following components by weight of the catalyst carrier:

further, the molar ratio of the element Mn to the element Ce in the low-temperature desulfurization and denitrification catalyst is 4: 1.

further, the content of Mn oxide in the low-temperature desulfurization and denitrification catalyst is 5-25 wt% based on 100% of metal oxide by mass; the content of the oxide of Ce is 1-4 wt%.

Further, the clay material is one or more of kaolinite clay, sericite clay and montmorillonite clay.

The invention also provides a preparation method of the low-temperature desulfurization and denitrification catalyst, which comprises the following steps:

(1) mixing 35 parts of montmorillonite clay, 25 parts of zeolite, 1.5 parts of ignition loss agent, 30 parts of diatomite, 2.5 parts of ferric oxide and 1 part of copper oxide according to a proportion, adding proper water, uniformly stirring into a mud shape, and naturally aging in a cool and dry place;

(2) the aged blank mud is subjected to compression molding or extrusion molding to obtain a required catalyst blank;

(3) naturally drying the green body in the shade for 24 hours, then placing the green body in a hot air drying furnace at the temperature of 200 ℃ for drying for 2 hours, and placing the dried catalyst green body in a muffle furnace at the temperature of 950 ℃ for 8 hours to obtain a multi-gap foam ceramic-based catalyst carrier;

(4) soaking the porous foam ceramic-based catalyst carrier in 35% nitric acid for acidification, wherein the soaking time is 2 hours;

(5) the active components of the catalyst are attached to the surface of the catalyst carrier by an equivalent impregnation method;

(6) calculating the weight of the required solution and the weight of various catalyst active components according to the water absorption of the catalyst carrier, wherein the weight of manganese acetate, cerium nitrate, copper sulfate and ferrous sulfate is 9 wt%, 3 wt%, 2 wt% and 1 wt%, respectively, and dissolving the components in a proper amount of water to prepare an aqueous solution containing the catalyst carrier active components;

(7) soaking a catalyst carrier into an aqueous solution containing active ingredients of the catalyst carrier for 2 hours, taking out the catalyst carrier, and drying the catalyst carrier at 200 ℃ for 10 hours;

(8) and (3) placing the dried catalyst in a muffle furnace at 950 ℃ for 8h to obtain the catalyst capable of removing CO, SO2 and NOx simultaneously. Further, the shape of the catalyst body in the step (2) is one or more of honeycomb shape, spherical shape and plate shape.

Further, the volume of the hydrochloric acid solution in the step (4) is equal to the water absorption capacity of the catalyst carrier.

Further, the drying method in the step (5) is one of hot air drying, infrared drying, microwave drying and natural drying.

Further, the heating temperature in the step (6) is 220-240 ℃.

Further, the heating temperature in the step (6) is 230 ℃.

Compared with the prior art, the invention has the beneficial technical effects that:

the low-temperature desulfurization and denitrification catalyst is prepared by using cheap clay and fly ash as catalyst carriers, carrying out nitric acid pre-oxidation (acidification), dissolving active ingredients of the low-temperature catalyst by hydrochloric acid, and then adhering metal oxides to the carrier of the low-temperature desulfurization and denitrification catalyst by an equivalent impregnation method. By controlling the heating temperature, the excellent lattice density of the active ingredients of the catalyst is ensured, the phase change which is not beneficial to catalytic reaction and is formed by metal oxides in the active ingredients is avoided, and the nitrogen oxide can be reduced without any additional reducing agent.

The low-temperature desulfurization and denitrification catalyst disclosed by the invention is simple in preparation process and low in cost, can realize the technical effect of desulfurization and denitrification, reduces the treatment cost and treatment difficulty of enterprises, and has a huge industrial application value.

Detailed Description

The invention will be further described with reference to the following examples of 4 ton gas boiler waste flue gas treatment by the Changyuan brewing Co., Ltd, Chengde, Hebei province, but it should be understood that these examples are for illustrative purposes only and should not be construed as limiting the practice of the invention.